schmiedel



Feb. 14, 1956 scHMn-:DEL

CENTRIFUGAL SEPARATOR 2 Sheets-Sheet 1 Filed April 24, 1951 Feb- 14, 1956 scHMlEDEL 2,734,681

CENTRIFUGAL SEPARATOR Filed April 24, 1951 2 Sheets-Sheet 2 A/fornqys trifugalseparatorfwill befequippedFWith- United States Patent@ r CENTRFUGLSEPRTR "Ludwig Schmiedel, Leipzig,Germany;'assignortoStarcosa Maschinenund .Apparatebau -Gesellschaft .mit Vbescliranktcr Haftung, `aucompany .of YGermany VApplicationApril24,5195, Serial No.3222`g595 1 Claims priority, `application Germany May-2,s1950 9 Claims. (Cl.)`233-"`"7) My invention relates ikto *la -1 centrifugal @separator fand more 'particularly "to f Sa t separator f f S'that f type provided lwith-a tapering drum rn'our'ited ltort-te J'-'about a -Sub stantially horizontal axis and serving to separate-"aI mix- 'f ture ofy solid' matter 'arida liquid.

In a separator of that type, the solid matterlwillJdefposit'on the internal wall ofthedrum andl-wi-llibe scraped olf'and discharged by-a feedin'g'lworm.

'iSuchlseparators Iservethe purpose (5f-#obtaining solids VAsuspended in a liquid. l In cases,howeverfwhere'fthe'solid *rnatter comprises more than-a-single:constituentreprerser'rting a v mixture Y of lcomponents:considerably fdiffering fromeach other, onel component f being fpossibly an l im- "purity of another :primary component, 'the additional problem arisesto cleanlyfseparate various-constituents of `|thersolidmattercoristitutingtheliriituredeposited. -More particularly, *such separation should #be -fca'rried 'lout vin :a

'mannerrwhereby the' primary 'constitue'ntflwill bei obtained lseparately :from the f impurity thereof. lFor' theapurpose "of solving that problem verycomplicate'd fand-'tedious A"methods 'havebeen developed l'retluiririgthe useiof-Sex- -terisive apparatus landrria'n'y f such methodsare open to the -objection `thatithe solids Sto be Aobtained will 'Ibe settling after a 'comparativelyshortttavelfwhereas the lsolids' having a lower'sinking speedfwillsettlefter.traveli'nga longer distance.

Thus, the present inverti'onaffodsfa possibilityofllsep- `arating ythel primaryconsti'tuent ofafmxture of solids ffrorn secondary constituents i constituting impurities,` such "solid impurities being vcarried away l'tog'ether Twith .lthe lliquid. InI the'descrpt-ionf my' invention followinghereinafter a primary constituent'tobe'producedinfpureconl dition willV betermed heavierf1'solid`, "'whereas i the Iother constituents being undesirableffadniixtures will @be called lightl constituentsl with liquid' to'be 'treated 'towards -aplanelintermediate `-its ends, such drum beinglfprtwidetlwith'a :discharge Worm. Whereas V"all prior1 separators 'ofkthat `r kind v`4v/ere so 'designed-as to 'decelerate Atheflow 'off'.liquidtowards the discharge :Send off thefzdrum, AI :endeavor Ito :accelerate such ow beyond? the; plane 2 ofI the largest cross v section Yof: the drum tof thereby increase: thefispeed of Ythe-I passage of theliquid through=the..-drum. :The means of attaining such increase fof .thef-'speedmfdlowy isagraduah reduction `of the cross section o f the drum between said plane and 2,734,681 .fBatentedisEeh f1.4, :i1-956 ice Ji. vthe v'discharge .end fof irthe f'rdrum 1'where I 'the irli'quid Lisf discharged therefrom. `I'h'e 'Ai'effect .so I'fattained4 fmay the 'ien- Tthanced by fa. reduction .of tthelevel lof @hei-annular TvWeir :provided at: such':dischargeendioflthe drum.

As the cross sectionfof the :drum decre'asestowardslthe .dischargeend of .the drum, th'e widthi of 2 the ldis'cliarge worm will likewise decrease? ini ordertopreventfthe 'Slight solids .fromsettlirrgwithn the.'comparativlyacalmrregions located between the`-worm.helices.

Preferably, "the :radial height :of .the weirtis :rendered variable .1 in lorder Ato properly-:control ythe 'zow iisp'ee'd of .the liquidzthroughlthefdrum. .Tothis iendgthe annular .member constituting :'.thewweir may be imountedtobe readily exchangeable.

In an embodimentiof .n'iyairiventionwhich has been found satisfactory for '.manyuuses, lthe f :discharge fend vof the .tapering drumlraving'a continuously2-taperir1'g .cross section is providedS-fwithiarriinternalcylindricalffacefwithin a'zone locatedifadja'cent tothefdisc'hargeend. Thewidth '.offthat .zone depends :on the.requrements1.of Iany particular case, :thescylindricalinternal '.face functioning at the *same .timeasfithe1-weir,lthe2orthodox aweir fof prior '-.designs .bein'g eliminated jseparation fof -the fs'olids :may fbe enhanced'by providing means -for 1 feeding fthe :in: starch facto'ries.

1 In: .the .drawings ,"Fig. :l issa-longitudinall section .through a Scentr'ifugal vseparator according lztoilthezinvention;

Fig. 2 is a partialsectionalillustrationfofa modied zdischarge= end 'rofzthe fdrum provided ivith :exchangel: able =weir;

:Fig.r3 is! a partial sectional viewz-'otstlllanotherembodiynient showing famoditidfeeding'eworm;

:Fig 4::is a partial?longitudinalrisectionofacentrifugal separator :in whichthe fend :of fther fdrumfunctionsias the aweir;

`iFig. "5' showsvat'partial longitudinalsectionlof alsepahaving i'ahand yop'posite'fto Ithatf'o'f the resti ofiY the `=wo'rrn.

Prior to myiinventioniitffwasCcustomarysin theproducytion 'of-:starch t'osepa'rate zther-slidamatter .in 12a-:centrif- .ugaliseparator'inaaitirstfoperatiomandfto;classifydhe solid matterinrset'tling troughsinfa isecond "operati-on. SMy

novel `centrifugal iseparators fdescribd fhereinafter are 4adaptedto carryffout'lbdth inea single operation.

.The centrifugalA sepanatoreillustrated in lFirg. llincludes ashaft Swdr'iverrifromia suitable :source oflpower `not `sh'own,l one end-Tofisuchlishaftibeingijournalled by means of'fa ballbearingfl in a1r 'suitableast-ationary supportnet shown, Akwhereas the otherrduced'endSZofthe: shaft wall '1`0`2 provided vlwith :a .central'aperture 'The"cen .t'ral aperture is surrounde'dby va `conical toasting `51,. 11)0 whihisintegral' with 'the end wall 102, radial ribs101 inside of said apertureandthe .head 53 raxially located "within the casting. A tubular extension'v 111 f-the castringf1, 100-co-aiially arranged with." respect .to -thehead T53' is journalle'd' by means of an .anti-friction bearing `112 in a suitable stationary support not shown.

The en"d wall102..s. provided Vwith appluralityrof ldisychargesoperiings .'12 "through villiich"the feed .worm tol beV 1described"hereinafter V'c'lis'chaiges the slid matter sep- 3 arated from the liquid fed into the drum through the central aperture.

Means are provided for collecting the solids issuing from the discharge openings 12, such means comprising, in the present embodiment, a hollow casting 13 which surrounds the casting 1 having two parallel end walls provided with co-axial openings, the opening of one end wall having a rim 130, while the opening of the other end wall accommodates the casting 1 suitably sealed thereagainst by sealing means not shown. The rim 139 surrounds the periphery of the end wall 162, same being so fitted therein as to freely rotatable. Preferably, the casting 13 is divided along a horizontal plane in two sections which are firmly connected by screws not shown.

The end wall 102 of the casting 1 is rigidly connected with a flange 20 of the rotary separator drum 2, 3. As will appear from the drawing, the drum is so shaped as to taper from a transverse plane intermediate its ends towards its ends. Preferably, the drum is composed of two adjoining sections 2 and 3 which taper towards the ends of the drum, the smallest diameter of the section 3 at the right hand end thereof viewed in Fig. l being in excess of the smallest diameter of section 2 at the left hand end thereof. Thus, it will appear that the drum sections 2 and 3 have a frustro-conical shape being rigidly connected to one another by flanges 21 and 31 and suitable screws not shown. The tapering end of the drum section 3 is provided with a peripheral flange 30 to which a flange 140 of a casting 4 is bolted, such cast- Ving constituting the other end wall of the drum. The

casting 4 is integral with an axial hub 40 freely surrounding shaft 5 and being journalled by an anti-friction bearing 41 in a suitable stationary support not shown. Thus, the two anti-friction bearings 112 and 41 will support the drum for rotation about its axis.

The end wall 4 is provided with a plurality of discharge openings 113 near its periphery, each of such openings communicating with ducts extending axially and outwardly and terminating in an outlet provided in a circular rim 15 formed by the casting 4.

Adjacent to the end wall 4 a collector 16 is mounted serving the function of collecting and discharging the liquid passing through the openings 113. The collector 16 is formed by an annular hollow casting having an inner peripheral slot which straddles the rim 15 at as close a spacing as consistent with the free rotatability of the drum. Preferably, the casting 16 is divided along a horizontal plane in two sections suitably connected to one another by screws not shown. The lower section is integral with a discharge tube 160 provided with a flange 19 attached to a suitable discharge pipe not shown.

Driving means are co-operatively connected with the shaft 5 and with the drum through the intermediary of the hub 40 and adapted to produce a relative rotationy between the drum and the shaft 5. In the present embodiment such driving means comprise a gear 42 attached to the hub 40, a gear 48 attached to the shaft 5, and two gears 43 and 47 which are attached to a shaft 44 extending parallel to shaft 5 and journalled in stationary supports not shown by means of anti-friction bearings 45 and 46, the two gears 43 and 47 meshing with the gears 42 and 48, respectively. As shown in Fig. l, gear 48 has a slightly smaller diameter than gear 42. Therefore, the operation of shaft 5 at a certain speed from a suitable source of power mentioned above results in the rotation of the hub 40 and of the drum carried thereby in the same direction but at a slightly different speed. y

The shaft 5 constitutes mounting meansvfor a feeding worm 11 mounting same for relative rotation within the drum 2, 3 substantially in contact with the inside of the drum sections. The worm 11 is preferably constituted by a helical strip which is rigidly connected by suitable holding members 200 with a tubular member which, in its turn, is rigidly connected with the shaft 5 by disks 6 and 8 connected thereto. The holding members 200 may be formed by axial and peripherally spaced rods which permit of a ready axial ow of liquid within the drum. Separate supporting means are provided in the present embodiment for the left hand end of the worm 11. For this purpose, the disk 8 attached to shaft 5 has radial outwardly projecting ribs 7 carrying a conical sheet metal member 9 to which the worm is rigidly connected by holding members in form of pins. The hand of the helical strip constituting the worm 11 is so chosen with respect to the driving means 42, 43, 47, and 48 that the Worm feeds the solids deposited on the internal face of the drum towards the left through the openings 12 into the casting 13.

The liange of the casting 4 extends inwardly beyond the flange 30 of the drum section 3 to constitute an annular weir 14 determining the substantially cylindrical internal level of the annular body of liquid forming in the drum 2, 3 when the same revolves at a high speed. It will be noted from Fig. l that both drum sections 2 and 3 constitute a peripheral drum wall free from any perforations.

The operation of my novel centrifugal separator is as follows:

The material to be treated is fed through the casting 1 into the conical sheet metal member 9 and passes therefrom through the passages 80 provided between the ribs 7 into the drum section 2 at a point intermediate the ends thereof. The liquid so fed will be accelerated in circumferential direction while passing to the plane of the joint between the drum sections 2 and 3 at a gradually decreasing speed, As the liquid passes through the drum section 3 towards the right, its peripheral speed will decrease, whereas its axial speed component will increase until the liquid reaches the Weir 14. By suitably dimensioning the diameter of the Weir and the shape of the drum sections 2 and 3 in relation to the quantity of the liquid supplied, the speed of flow will be so controlled and increased, as the liquid approaches the weir 14, that the heavy solids will settle on the wall of the drum section 3, while the lighter solids will be carried away by the liquid across the weir 14. The heavy solids deposited on the internal wall of the drum are scraped off by the feed Worm 11 and are fed to the left being ultimately discharged through the openings 12 provided in the end wall 102. There the solids are collected by casting 13 and discharged through suitable tubes not shown.

Fig. 2 illustrates a modified form of the weir, same being constituted by an exchangeable annular member 17 interposed between the anges 30 and 140. By electing an annular member 17 of appropriate diameter and by inserting same, the internal level of the annular body of liquid forming in the drum may be so determined as to result in the desired axial component of the speed of flow of the liquid through the drum.

It will be readily appreciated that the Width of the helical strip constituting the worm 11 influences the axial component of the speed of flow, a free flow being possible between the internal diameter of such strip only and between the internal level of the annular liquid body. in the space between the helices of the Worm the liquid has no substantial component of iiow in axial direction. Therefore, light solids are liable to settle at such points since they are no longer carried away by the current. Under adverse circumstances the result might be an insuiiicient solution of the problems discussed supra, the impurities not being removed to the extent required.

Therefore, I prefer under certain conditions to use the embodiment illustrated in Fig. 3 in which the width or radial dimension of the helical strip tapers towards the discharge openings 113. As a result, the proportion of the cross section available to the axial ow component in relation to the entire cross section between the internal face of the drum section 3 and the internal level of the liquid will be increased towards the discharge openings sgr/amel 113, yfthe Slayer of liqid sentrapped fbetween tithe helices foff the 'lworm beinfg: graduallyfireduced tarrthesame time. Consequently, the lighter solids will not be permittedfto settle but will be carried away by the supporting liquid. As in this vembodimenttlfersettlingpath y'of fthe 1 particles will be the shorter Lthehighertthe axial 'Scomponent of the Ailow will be,.the heavy particles-will nevertheless-settle aan :the internal face of the 'drum sec-tion 3, particularly inasmuch .asfbut a small quantity ffheavy particles'will be suspended in the liquid near 'the .dischargeendproyvided 'with the openings T13. 'Inf-.this embodiment the height of the weir mayn be made particularly low.

In certain materials'-alargerlproportion of compara- ;ti-velyismallgparticles may result intareduction rof the uqualityofthe primary componentssought. 4=illus trates an embodiment in which the helical strip constituting the worm 11 does not extend up to the end of drum section 3 but terminates at some distance therefrom. Moreover, drum section 3 is so shaped that the rim 33 at the end thereof constitutes the weir. As a result, so large a flow speed will be attained near the end of the drum that, in addition to the light particles, heavier particles will be carried away by the liquid.

If desired, a larger proportion of the relatively small particles may be separated in a machine of the design illustrated in Fig. 5 in which a number of helices near the discharge end of drum section 3 may have a hand opposite to that of the rest of the worm so that the solid matter settling within the range of such helices will be fed to the discharge end 33 and will be carried away by the liquid.

Moreover, the drum section 3 may be so shaped as to form an internal cylindrical face within a region located adjacent to the rim 33.

While I have described my invention by reference to a number of preferred embodiments thereof, I wish it to be clearly understood that the same is not limited to the details of such embodiments, but is capable of numerous modications within the scope of the appended claims.

What I claim is:

l. A centrifugal separator comprising a horizontally disposed rotary drum tapering from a transverse plane intermediate its ends towards its ends, the peripheral wall of said drum being free from perforations, means mounted adjacent to one end of said drum to feed the liquid to be treated into the latter, a collector mounted adjacent to the other end of said drum and adapted to collect and discharge the liquid issuing from such end, a discharging worm of helical strip form mounted for relative rotation within said drum substantially in contact with the inside of said peripheral wall and adapted to feed axially the deposits separated from said liquid out of at least one end of said drum, means co-ordinated to said last mentioned end of said drum and adapted to collect the solids discharged therefrom by said worm, and means for rotating said drum and said worm about a horizontal axis.

2. A centrifugal separator comprising a horizontally disposed rotary drum composed of two adjoining sections tapering towards the ends of the drum and being free from perforations, end walls mounted on said drum for common rotation therewith, said end walls being provided with discharge openings for the discharge of material from said drum, one of said end walls having an aperture for charging said drum with liquid to be treated, a discharging worm of helical strip form mounted for relative rotation within said drum substantially in contact with the inside of said drum sections and adapted to feed axially the deposits separated from said liquid towards at least one of said end walls and through said discharge openings therein, collecting means co-ordinated to at least one of said end walls and adapted to collect the solids issuingfrom said discharge openings, a collector mounted adjacent to the other one of said end walls and adapted to collect and discharge the liquid passing through the =mienings Eprovided l'therein, Y:arid :..means for rotating fsaid .drumiand Vsaid worm about 1a.hor-izontal axis.

A fcentrifugal separator comprising .a.horizontally l disposed rotary drumlhaving a-. .peripheral .wall-freelfrom fperforations, means-amounted:adjacentto one-end-1of y-said drum tofeedthe-liquid to.bel-.treated=into-the.latter, means .mountedon the other .endiioftsaid -drumfconstituting an annular weir adapted to determine the.substantiallyecylindricalz .internal leveliof theY annular body-.ofgliquid formningtinasaiddrumwhenthe.sarne` revolves-at a' high speed, na discharging worm `offlrelicalcstrip form.mounted.ffor v relative rotation `within ,said `drum .substantially .in contact with the inside of said peripheral walhandfadapte'd `to i feed axially 1 thefdeposits :separated .from :said liquid A out noffsaid-1drum,.rneansf.coforilinatedto atleasLone Vend .of said drum and adapted to collect the solids (fed out f said drum by said worm, the internal diameter of said drum being smaller near the ends thereof than intermediate said ends, a collector mounted adjacent to said weir and adapted to collect and discharge the liquid passing thereover, and means for rotating said drum and said worm about a horizontal axis.

4. A centrifugal separator comprising a horizontally disposed rotary drum composed of two adjoining sections tapering towards the ends of the drum and being free from pcrforations, end walls mounted on said drum for common rotation therewith, said end walls being provided with discharge openings for the discharge of material from said drum, one of said end walls having an aperture for charging said drum with liquid to be treated, an annular Weir co-ordinated to the other one of said end walls and adapted to determine the substantially cylindrical internal level of the annular body of liquid forming in said drum when the same revolves at a high speed, a discharging worm of helical strip form mounted for relative rotation within said drum substantially in contact with the inside of said drum sections and adapted to feed axially the deposits separated from said liquid towards at least one of said end walls and through said discharge openings therein, means co-ordinated to at least one of said end walls and adapted to collect the solids issuing from said discharge openings, a collector mounted adjacent to the other one of said end walls and adapted to collect and discharge the liquid passing through the openings provided therein, and means for rotating said drum and said worm about a horizontal axis.

5. The combination set forth in claim 4 in which said weir co-ordinated to the other one of said end walls and adapted to determine the substantially cylindrical internal level of the annular body of liquid forming in said drum when the same revolves at a high speed is constituted by an internal flange of said last mentioned end wall, the latterbeing formed with a hub, a rotary shaft being provided freely extending through said hub and carrying said worm.

6. A centrifugal separator comprising a horizontally disposed rotary drum tapering from a transverse plane intermediate its ends towards its ends, the peripheral wall of said drum being free from perforations, end walls mounted on said drum for common rotation therewith and provided with discharge openings, one of said end walls having an aperture for charging said drum with liquid to be treated, a discharging worm constituted by a helical strip, a tubular member, mounting means for lmounting said tubular member co-axially within said drum for relative rotation thereto, spaced holding members constituting a rigid connection between said tubular Y 7 discharge the liquid passing through the openings provided therein, and means for rotating said drum and said worm about a horizontal axis, said last means being co-operatively connected with said mounting means and with said drum to produce a relative rotation therebetween.

7. The combination claimed in claim 6 in which the width of said helical strip tapers from the greatest diameter of the drum towards the end of the drum where liquids are discharged.

8. The combination set forth in claim 2 in which the internal face of one of said two adjoining drum sections which tapers towards said other one of said end walls terminates in a substantially cylindrical Zone adjacent to said collecting means.

9. The combination set forth in claim 2 in which said rotary drum has an internal cylindrical face within a zone adjacent to said other one of said end walls and is continuously tapering from a plane located intermediate its ends towards said zone and towards said one of said end walls.

References Cited in the tile of this patent UNITED STATES PATENTS 775,320 Van Kirk NOV. 22, 1904 924,376 Phillips June 8, 1909 2,458,706 Howe Jan. 11, 1949 2,528,974 Ritsch Nov. 7, 1950 2,600,372 Milliken June 10, 1952 FOREIGN PATENTS 539,140 Great Britain Aug. 28, 1941 653,056 Germany Nov. 13, 1937 

